Drill mounting



Aug. 20, 1963 E, H, KURT 3,101,006

DRILL MOUNTING v Filed oct. 1s, 1960 ssheets-sheetl INVENTOR E'WALD KURT Wm T ORNEY HIS r N O` ON .Q N N V E. H. KURT 3,101,006 i DRILL MOUNTING Aug. 20, 1963 s sheets-sheet 2 Filed Oct. l5, 1960 INVENTOR E. H. KURT DRILL MOUNTING Aug. 20, 1963 3 Sheets-Sheet 3 Filed 00T.. 15, 1960 H. KUR T INVENTOR EWALD United States Patent (y) 3,101,606 DRILL MOUNTING Ewald H. Kurt, Phillipsburg, NJ., assigner to` Ingersoll- Rand Company, New York, NY., a .corporation of New Jersey Filed Get. 13, 1960, Ser. No. 62,361 2 Claims. (Cl. 74P-424.8)

This invention relates to mountings for rock drills, and particularly for rock drills'of .the percussive type which are adapted lto acuatea rod `extending therefrom.

Drill mountings of the type'to which this invention re-l lates are often relatively `long to enable drill rods to he used which are adapted to operate continuously to drill a relatively deep hole without changing of the rods. Such mountings usually comprise a guide member upon which the drill is slidingly mounted and advanced by means of a feed screw. Tlhe feed screw and the drill rod Iare both long and :are therefore relatively llexible and free to vibrate. Vibration of the drill, feed screw and the drill rod causes excessive wear on the feed screw, as well as loss of power due to the flexing of the drill rod.

It is an object of this invention to eliminate or at least to minimize vibration and flexing of the drill rod and feed screw.

To this end in a preferred embodiment of the invention, a centralizer is movably mounted on the .guide shell which acts as a steady nest for the feed screw and for the drill rod. Means is provided to advance the cen- -tralizer as the drill advances, but at a slower rate of speed than the drill so that it will continue to support these elements at an intermediate point of their unsupported length, throughout the travel of the drill `along the Iguide shell.

'Fhe invention will be more completely understood by 3,1 l ,0116 Patented Aug. 2i), 1963 ice I able motor 20. l

This invention provides a second centralizer 22 intermediate dnill 12 and the forward centnalizer 16 and slidableV on -guide 10. "lThis centralizer22 not only acts as a centralizar or steadyrest for rod 14 but is actuated by and acts as a steady rest for the feed screw 18.

For slidingly-supporting drill 12, the guide shell 10 is provided; with grooves 23 to receive laterally extending wings 24 formed at the rear of drill 12. Ithas also a longitudinally extending trough 26 to receive a boss 28 extending downwardly from drill 12 and which is inserted the usual feed nut 3tlfor engagement with feed screw 18. Nut 30 is held in place `in boss 2S by a lock nut 3-2.

lu the -usual manner rotation of feed screw 18 advance drill y12. To drive the feed screw 18, a motor 2E) is `mounted rearwardly of guide shell 10 andengages feed screw 18 by means of a chuck 3o formed integrally with the motor shaft 38 and iluted as at 4U to engage the iluted end 42 of feed screw 18'. The thrust of feed screw 18 is taken by chuck 36 vand the rearI face 44 of chuck 36 bears against a collar 46 mounted on motor shaft 33 and abutting motor bearing 48. The bearing 48 is flanged at 50 to bear against the housing end 52 of motor 29.

The front end of feed screw 13 is similar to 4the rear zend, and has its fluted end 42 iitting into the fluted portion 54 of a bearing plug S6 with the endwise thrust being taken by the bottom` face 58 Within plug 56. Bearing plug 56 is rotatably mounted in a bracket 6i) having a referenceto the `following description taken with the tion taken along the line 2--2 of FIGS. 1 and 3 looking i i-n the `direction @of the arrows,

FIG. 3 is a longitudinal vertical section at the driven l end of the feed screw showing por-tions of the driving moto-r and the rear end of the dnill,

FlG. 4 is a cross section taken at the line 4-4 of FIGS. 1 and 5 looking in the direction of the arrows,

FIG. 5 is a longitudinal vertical section of Ithe centralizer,

FIG. 6 is la cross section through the forward end of the feed screw and guide shell taken along the line 6v-6 of FIGS. l and 7 looking in the direction ofthe arrows, and

FIG. 7 is a longitudinal vertical section `of the feed screw at its front end and the :guide shell.

Referring to the drawings, FIG. l indicates the type of drill mounting and drill to which this invention relates, it being adapted to be used in conditions where very deep or relatively deep drill holes are desired, whereby the use of correspondingly long lengths of drill rods or steels minimizes `the changing of steels. As indicated, a drill guide 10 slidingly supports a percussive .type of drill 12 at the fonward end of which pnojects aa drill rod 14 extending longitudinally along the drill guide 10. Alt the forward end of guide shell 10 Iis provided a centralizer 16 of conventional fonn by which the forward end of drill rod 14 is steadied in the vicinity of the mouth of the drill hole (not shown). A feed screw 18 threadingly bore 62 to receive" plug 55, the end face 64 within bore 62' being adapted to tak-e the thrust of bearing 56.

For attachment to shell 10, `bracket 60 is provided with a ange 66 which it Ibolted by cap `screws 68 to the end face of the guide shell. l

From the above description it will be obvious that as drill 12 is advanced by rotation of feed screw 18, the rear end face of feed screw exerts pressure against chuck 36. On lwithdrawal of `drill 12 by reversing the direction of `rotation -of feed screw 1S, the front end of feed screw 1S is under compression and is apt to buckle unless properly steadied. Likewise as drill 12 advances, drill rod 14 is under compression and, being very long, there is likewise the tendency for it to buckle, such flexibility resulting in a loss of power. Centralizer 22 is adapted to obviate these conditions. i

of. The forward end of the body portion 'TO'..terminates 1 l a Idrill steel receiving portion'in the form of a loose clamp having a stationary ja'w Sil and a hinged jaw 82 having a hinge pivot 84. The swingable jaw 82 permits insertion of drill rod 14 within a two part bushing 86 loosely conforming to the outer diameter of drill 14 and held. in portions and 82 of the clamp. A clamping bolt L88 is pivotally mounted at 90 in the stationary jaw 80 and extends through jaw 82 to hold the jaws together.

Means is provided to advance drill 12 and centralizer 22 at different speeds, that is to say, centralizer 22 is preferably advanced more slowly than drill 12. lin this instance, it is desired that the centralizer move about half as fast as drill 12. To this end, feed screw 1.8 is provided withtwo sets of superposed threads 94, 965, one having half the pitch of the other, assuming eaclh is a single thread. lt is of course possible to obtain the same result in an arrangement in which, lfor example, the nut 30` has y of the invention.

Vwill cause the nut 313 to move 1.5 inches (3 .5) and the nut 76 will move .7 5 inch. In any event the thread combination is Ichosen such that as fee-d screw i3 rotates,

Ydrill 12 will advance more rapidly than centralizer 22, the .latter-remaining substantially midway of the unsupported 4length of drill rod-1f4 ando-i feed screw 1S thereby cuttingwdown vibrationof those two elements. Means is provided to prevent sudden shock as drill 12 reaches the end ofits travel on retraction by `iced screw Y anciens the guide shell 1d isz advanced with respect to the clam-p so asV to bring the drill again to the rear of the guide shell and continue drilling. Y

Thus, by the above construction are accomplished, the objects hereinbeiore Vreferred to.

lclaimzn i 1. A mounting ,for a rock'drill of the percussive type having a f=`drill,',.rod extending therefrom, comprising a 18. To this end, chuck 36 is provided with -a'sleeve Vllti held'forwardlyv thereon by a very stiii spring liilZ encircling chuck 36 and bearing against collar at its rearward end. Buffer Vsleeve 19% is adapted to project beyond chock 36 and to engage nut 32 with sufiioient resistance to overcome the power. of motor 2d and thus avoid injury due t-o jamming of feed nut' 32 against chuck 36. To Vhold vsleeve 16d' in place, that sleeve Vis provided with internal shoulder lll@ to engage an external shoulder 165 on chuck 36.l

The threads of feed .screws become wom inasmuch as than those inthe other, and agreat advantage of this construction is that feed screw 18 can be reversed since it is in design exactly Vthe same `at the two ends.

That part of the apparatus on which the .guide shell 19 is adapte-d to tbe mounted is not shown at it is not a part However, it may `be remarked that extending longitudinally of shell Mil are continuous div vengent clamping vfaces 119 for attachment to aV suitable Vclamp (not shown).v In practice this sort of guide shellV i0 isslidaible Von such -a clamp so that a drill steel of sub-V stantially twice the length ofthe guide shell can be used continuously. The usualpractice is to start with the guide shellpclamped at its `front end and with lthe drill at the rear, drilling until drill 12 reaches the front endof the .the lpressure, applied inV one direction are usually greater i Y Vguide shell, Whereupomleaving the drill in that position, g

V.the centralizer guide shell'slidinglyV supportingsaid drill, Va centralizer for the drillirod slidingly supported by `the guide shell, and ineens cooperative with said guide shell to advance said fdrill and said centraiizer simultaneously at different rates of speed with respect to each other `and the-:guide including a feed screw having ltwo threads vofdiiierent pitch one long and the other short engagingrthe drill and respectively, and means to rotate 'said `feed screw. v 'g l J f2. A mounting for arook drill appanatus ofthe per-V missive-type comprising: a drill; an elongatel `guide shell slidably supporting said drill; an elongate drill rod conneeted to and extending from said drill along said guide shell; a `drill rod lcentralizer slidably Vmountedvon said guide shell and supporting said drill rod; and :drive means including a Ifeed screw rotatably mounted on said guide shell and threadably engaging 'said tdnill and said centralizer, said feed screw having two supenposedfthreads of diferent -pitch with Ithe larger pitch thread engaging and dri-ving the drill and the small pitch thread` engaging and driving the lcentralizer at a slower speed relative to the ,driving speed of the drill.

VReferences Cited in t'ne ilexof this patentV UNITED STATES PATENTS 2,079,189 Simpson et al. May 4, 1937 2,434,120 Paget Ian. 6, 1948 2,644,669 Curtis et al. July 7, ,1953 2,958,514 

1. A MOUNTING FOR A ROCK DRILL OF THE PERCUSSIVE TYPE HAVING A DRILL ROD EXTENDING THEREFROM, COMPRISING A GUIDE SHELL SLIDINGLY SUPPORTING SAID DRILL, A CENTRALIZER FOR THE DRILL ROD SLIDINGLY SUPPORTED BY THE GUIDE SHELL, AND MEANS COOPERATIVE WITH SAID GUIDE SHELL TO ADVANCE SAID DRILL AND SAID CENTRALIZER SIMULTANEOUSLY AT DIFFERENT RATES OF SPEED WITH RESPECT TO EACH OTHER AND THE GUIDE INCLUDING A FEED SCREW HAVING TWO THREADS OF DIFFERENT PITCH ONE LONG AND THE OTHER SHORT ENGAGING THE DRILL AND THE CENTRALIZER RESPECTIVELY, AND MEANS TO ROTATE SAID FEED SCREW. 